Screw threading apparatus



Dec. 23, 1952 M. WERNLI SCREW THREADING APPARATUS 2 SHEETS-SHEET 1 FiledDec l8,- 1946 De c. 23, 19 52 M. WERNLI 7 2,622,252

SCREW THREADING APPARATUS Filed Dec. 18, 1946 2 SHEETSSHEET- 2 Fig. 4 v

Patented Dec. 23, 195.2

Max Wernli, Schaifhausen, Switzerland, as: signer to Aktiengesellschaftder Eisen und Stahlwerke vormals Georg Fischer, Schaifhausen,Switzerland Application December 18, 1946, Serial No. 717,056 InSwitzerland January 25, 1946 2 Claims. (U1. 10-105) My present inventionrelates to improvements in manually operated screw-threading apparatuscomprising a rotary and axially displaceable diehead, on the spindle ofwhich an externally threaded sleeve is detachably secured, which latteris engaged by a threading guide nut detachably secured to the casing ofthe apparatus. The objects of my improvements are first, toprovidefacilities permitting of adjusting the chasing speed to the nature ofthe material to be cut so as to enable the operator to perform thescrewth-reading operation on blanks of diiierent material under asubstantially uniform physical effort, and second to alTord means forreadily exchanging the master-thread assembly and for positivelylocating the latter without backlash or slack.

I attain these and related objects by the apparatus shown, in two formsof invention and by way of example, in the accompanying drawing, inwhich Fig. 1- shows a first form in vertical section,

Fig. 2 a top plan View thereof, partly in ho'rizontal section,

Fig. 3- a cross-section on line A-A of Fig. 1,

Fig. 4 a second form in elevation, partly in vertical section, and

Fig. 5 a topplanview thereof.

In Figs. 1 and 2, l denotes the casing of the apparatus, 2 the die head,3 the spindle of the latter which is fastly secured to head 2, 4 aninternal gear, and 5 is the hub of the latter, which faces head 2. Hub 5is mounted rotatably in an axial bore of the hub portion 48 of casing land nonrotatably, but in a sliding fit on keys 6 sunk into spindle 3 andbeing engaged in grooves of hub 5; such arrangement permittingcf thenecessary axial displacement of spindle tin hub 5 of gear wheel 4. Theweb disc 59, interconnecting internal' gear 5 and hub 5, is abuttingagainst hub portion 68 of casing l. A ring so, keyed to hub 5 ofinternal gear abuts on one side against hub" portion id of easing l and"is provided with a helical groove 51 on its outside face, a slide block52 being engaged therein. A clamping screw 58, screwed into the slideblock 52, extends through a circumferential slot 57 provided in a hubportion 53 of an annular cam disc 54 which surrounds the ring 50'. whenthe screw 58 is tightened the cam disc 55 is rigidly connected to thering Eli, and accordingly the ring 59 and the die head '2 rotatetogether with the cam disc hi l. The latter is provided with ledges 55,projecting from the head face thereof and curved in plan, which areengaged in grooves of the chasers 58. The latter are guided, radiallydisplaceable, in

splines of head 2. When the clamping screw 58' is loosened, the cam disc54, owing to the circumferential groove 51, can effect a limitedmovement of rotation with respect to the ring 59; and since the slideblock 52 is engaged in the helical groove 5| of the ring 50, an axialdisplacement of the die-head and spindle 3 will result in a slightangular displacement of the cam disc relatively to the die-head and in acorresponding radial adjustment of the dies. Hub 5 also could be madeintegral with ring 50, and wheel 4 be mounted thereon. It also ispossible to make ring 50, Hub 5 and wheel 4 of one piece, in which casecasing 1 comprises two detachable and disconnectible half rings so as topermit of mounting the onepiece part described. An exchangeableandexternally threaded sleeve 8 is mounted on portion '1 of spindle 3projecting to the rear from wheel 6 and secured thereon. A cylindricalscrew nut 9, provided with threads identical to those of sleeve 8, isscrewed onto the latter and supported in a cylindrical bore of casing l.A terminal rear flange it is abutting against the rear face of casing iwhen the apparatus is in operation. A pawl i2 is fulcrumed at II oncasing I, and its nib or lug l3 abutsagainst the rear face of flange toof nut 9 so as to axially lock the latter in qasj ing I. By replacingthe master-screw assembly 8, 9 by one of differentpitch, the blankworked on is provided with corresponding threads. I Nut 9 sucharrangement not only serves guide for sleeve 8, butalsd as bearing forportion 1 of spindle 3 of die-head}. Sleeve 8* is axially secured by anut l4 screwed onto a threaded portion l5 of portion 1. The end of the,latter, adjacent to the threaded portion i5,- is formed as a square headIt, and may be engaged in the square socket of the hub of a hand leverll. Rotation of nut 9 relative to casing l is. prevented by pawl l2entering a groove [8' (Fig. 3') provided on flange Hi of nut 9. Themaster-screw asse'l'oibl'y -8, 9 thus is firmly secured in casing I, ofthe ap paratus and only sleeve 8 may move axially, together with spindle3, 1, l5, l6 and die-head. 2

A pinion l9, keyedv to the axle pin 29 which is journaled in casing l,engages the internal gear 4. The free end of axle 20', projecting beyondcasing [,is formedas a'square'headl l whicfiniay be engaged by handlever 11. A pinion 252, being of' greater diameter than pinion i9 anddiametrically opposite thereto, also engages rim gear 4. Pinion 22 iskeyed to axle pin 23 which is journaled in casing l. The free end ofaxle 23, projecting beyond casing I, is shaped as a square head and maybe engaged by the socket hand lever II. By such arrangement, spindle 3'and diehead 2 may either be rotated directly or by way of axle pins or23, in accordance with the nature of the blank material to be threadedby chasers 55, so as to require a substantially uniform physical efiortfrom the part of the operator in case of different blank materials ordiameters or types of threads.

When screw 58 is tightened fast to part 53, rotation of the spindle willcause it and the die head to move forward (left) as a result of the leadscrew action. Forward movement of the die head carries with it cammember 53-5455. This forward movement of 53-54-55 causes part 52 toreact with slot 5| thereby turning the cam member thus causing thechasers to withdraw at a rate proportional to the angle of slot 5| andthe rate of feed produced by the lead screw.

In the form of invention shown in Figs. 4 and 5, denotes the casing, inwhich the hollow hub 26 of internal gear 27 is mounted rotatably,coaxial to the central operating spindle of the screw-threadingapparatus. The end of hub 28 of internal gear 27, facing the rear end ofthe apparatus, is provided with a square socket 28 in which thesquare-head boss of a crank handle 29 may be inserted. A pinion 39, theaxle pin 3| of which, mounted rotatably in casing 25, is provided with asquare socket 32, meshes with gear wheel 21'. Socket 32 also may receivethe square-head boss of crank handle 29. A second pinion 33,diametrically opposite to pinion 33 and of greater diameter than thelatter, meshes with gear 21, and its axle pin 34, mounted rotatably incasing 25, is provided with a square socket 35 adapted to engage thesquare-head boss of crank handle 29.

The spindle of die-head 35 comprises three portions 31, 38 and 39. Thefront portion 31 carries the die-head 38, the center portion 38 carriesthe externally threaded sleeve 40 co-acting with the corresponding nut4|, and the rear portion 39 is adapted as square-head slidably guided ina corresponding square socket of hub 26 of gear wheel 21. Master-nut 4|is held fast in a chuck 42, 43 which is anchored in casing 25. The topportion 42 and the bottom portion 43 are hinged on a pin 44, and may bedrawn together, for fixing master nut 41, by means of a clamping screw45. The spindle portions 31 and 39, at their ends facing the centerportion 38, are provided with T-heads 45 engaged in correspondinglyadapted recesses provided on the faces of center portion 38. When chuckportion 42 is swung open, the spindle portion 38 comprising themaster-nut assembly 40, 4| may be withdrawn upwardly from or be inserteddownwardly between the other spindle portions 31 and 39. The T-heads 43allow the three spindle portions 3'I39 to rotate and move axially asunit. The front spindle portion 31 is mounted rotatably in a ring 47which is secured to casing 25 of the screw-threading apparatus.

What I claim and desire to secure by Letters Patent is:

1. In a manually operated threading apparatus having a stationarycasing, the combination with a rotatable die-head, of a rotatablymounted die-head spindle rigid with the die-head and axially movabl insaid casing, a lead screw on said spindle, a lead nut for said screwmounted '4 in said casing, said lead screw being formed by an exteriorlythreaded sleeve exchangeably engaged over the rear end portion of saidspindle remote from the die-head for rotation with the spindle, means onsaid spindle for holding the lead screw against axial displacementthereon, said means including a threaded end portion of the spindleprojecting axially beyond said lead nut and outside of said casing and anut screwed thereon and abutting against the rear end of the lead screw,said lead nut having said lead screw threaded therethrough and beingsupported by and removably engaged in said casing, said lead nut forminga-rear bearing for radially supporting the rear end portion of thespindle, and means provided on the rear end of the spindle forengagement with a manual spindle driving member, and interlocking meansaccessible from outside of the casing for locking the nut againstrotation relative to the casing.

2. In a manually operated threading apparatus having a stationarycasing, the combination with a rotatable die-head, of a rotatablymounted die-head spindle rigid with the die-head and axially movable insaid casing, a lead screw on said spindle, a lead nut for said screwmounted in said casing, said lead screw being formed by an exteriorlythreaded sleeve exchangeably engaged over the rear end portion of saidspindle remote from the die-head for rotation With the spindle, means onsaid spindle for holding the lead screw against axial displacementthereon, said means including a threaded end portion of the spindleprojecting axially beyond'said lead nut and outside of said casing and anut screwed thereon and abutting against the rear end of the lead screw,said lead nut having said lead screw threaded therethrough and beingsupported by and removably engaged in said casing, said lead nut forminga rear bearing for radially supporting the rear end portion of saidspindle, means provided on the rear end of the spindle for enagementwith a manual spindle driving member, and a locking pawl pivotallymounted on the casing and interlocking with the rear end of said leadnut for axially and rotatably locking the nut in the casing.

MAX WERNLI.

REFERENCES CETED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 153,770 Heap Aug. 4, 1874 270,409Forbes Jan. 9, 1883 280,575 Castle July 3, 1883 948,102 Walter Feb. 1,1910 1,053,482 Dreier Feb. 18, 1913 1,190,768 Joslin July 11, 19161,746,266 Klausmeyer Feb. 11, 1930 1,747,418 Bishop Feb. 18, 19301,969,854 Pealer Aug. 14, 1934 2,046,991 Zeller July 7, 1936 FOREIGNPATENTS Number Country Date 571,140 Great Britain Aug. 8, 1945 17,434Great Britain Sept. 18, 1895

